Adding an MCP server
- Open your agent → Tools tab → MCP Servers section.
- Click Add MCP Server.
- Configure the connection:
- Save. The agent will now see those tools on its next run.
Transports
- Streamable HTTP — modern transport; supports streaming responses over a single HTTP connection. Use this if your server supports it.
- SSE — Server-Sent Events. Fine for many existing servers, slightly older shape.
Tool filtering
By default, every tool the MCP server advertises is exposed to the agent. For big servers (10+ tools), that can bloat the prompt and confuse the model. Two ways to trim:- Tool Filter — explicit allowlist. Only the named tools are exposed.
- Deferred Tools — keeps definitions out of the system prompt until the agent calls
load_tool(name). Lets you attach huge tool catalogs without paying for them in every turn. See Deferred Tools.
Approval gating
Mark any sensitive tool (delete, send, transfer, …) as Requires Approval. When the agent tries to call it, the run pauses and the tool call is queued for human review. See Human in the Loop for the full workflow.Multiple servers
You can attach as many MCP servers as you need — internal corporate MCPs, third-party developer MCPs, single-purpose helpers. Each is configured independently and contributes its filtered tool set to the agent’s combined tool catalog.Relation to other tool types
- Connectors — HasteKit-managed, first-class OAuth integrations (Gmail, Slack, Jira, …) with per-user authorization. Use these when you’d rather not run an MCP server.
- API Servers — point at an OpenAPI 3.x spec and every operation becomes a tool. Use these when you control an HTTP API but don’t want to wrap it in MCP.
- Provider Tools — built-in tools (image, speech, web search, etc.).